Supplementary Material for: Mortality of epilepsy in Chinese populations: a comprehensive review

Background: Premature mortality is a significant part of the epilepsy burden and may vary across populations, especially between high-income and lower- and middle-income countries. People with epilepsy in China are approximately a fifth of the global population with epilepsy. Previous studies were unlikely to represent the situation in China due to limitations in design, methods, sample size, follow-up time, and other inherent population heterogeneity.
Summary: By summarising the evidence on the mortality characteristics in Chinese populations with epilepsy in the last six decades, we found a median mortality rate of 14.7 (6.8-74.4)/1000 person-years and a median standardised mortality ratio (SMR) of 4.4 (2.6-12.9) in population-based studies, and a median mortality rate of 12.3 (9.5-101.5)/1000 person-years and a median SMR of 3.0 (1.5-5.1) in hospital-based studies. Vascular diseases, complications of diabetes, and accidental injuries were the leading causes of death. Risk factors for mortality were reported as older age, male, longer duration and higher frequency of seizures. Case fatality ratios of status epilepticus (SE) in adults were higher than in children, and both increased with follow-up time. Mortality in people with symptomatic epilepsy was high and varied across different primary diseases.
Key Messages: The highest mortality rate and sudden unexpected death in epilepsy (SUDEP) incidence were reported from the least developed areas in China. Accidental injuries were the most common causes of epilepsy-related deaths, while the incidence of SUDEP may be underestimated in Chinese populations. Further research is warranted to improve the understanding of premature mortality risk so that preventative measures can be introduced to improve the situation.